1. Field of the Invention
The system of the present invention relates to meters in general and, more particularly, to dipmeters.
2. Description of the Prior Art
Standard three or four arm dipmeters are not used effectively to invert mud type drill holes. These dipmeters use electrodes to inject and detect the current flow in the formation near each dipmeter pad. Since oil and air are insulators, no electric current can reach the formation of interest. This results in a practically useless dipmeter survey.
The dipmeter of the present invention provides apparatus and method for making dipmeter measurements which overcome the operational problems in making dipmeter surveys in oil or air drilled holes.
U.S. Pat. No. 3,388,323 issued to A. A. Stripling appears to be similar in construction. However, the concept of operation differs. The Stripling patent requires that coils 91, 92 and 93 have high permeability cores. Coils having high permeability cores are extremely temperature sensitive and pressure sensitive. Temperature and pressure changes within a borehole represent a major problem. Further, Stripling investigates the magnetic properties of the medium and as such they must operate at low frequencies below a few kilohertz. Stripling measures magnetic susceptibility and conductivity whereas the apparatus of the present invention measures resistivity and dielectric constant.